Lawn mower gear and locking device



April 6, 1948. P N 2,438,980

LAWN MOWER GEAR AND LCBCKING DEVICE Filed July 31, 1946 3 14/0 e/wbo'nWang's E. Ham 150a eceas P4 Patented Apr. 6, 1948 UNITED STATES PATENTOFFICE 7 .LAWN MOWER GEAR AND LOCKING DEVICE Francis Edward Thompson,deceased, late of Lawrence, Mass., by Albert E. Thompson, administrator,Methuen, Mass.

Application July 31, 1946, Serial No. 687,383

The invention relates to aflgear clutch, and more especially to alawnmower gear and looking device. l

Theprimary object of the invention is the provision of a device of thischaracter, wherein its structure is a refinement overthe subject matterof Letters Patent No. 2,383,696, dated August 28, 1945, in that a morefirm locking is 7 had between the gear and the power shaft, due

to the'formation of the looking or clutch roller, and ;there is noliability of unclutching action of. the latter, resultant from grease orother lubricant depositing thereon and the surface adjacent thereto,during theoperation of the said device. V l 1 Another object of theinventionis the provision of a device of thischaracter, wherein thetensioning spring for the clutch roller is anchored thereto in a novelmanner, so that repairscan be made, when the spring breaks with ease anddispatch, in that when the spring breaks under the constructiondisclosed in Letters Patent No. 2,383,696, there is no possible way ofsubstituting a new spring in use with the gear, as the latter has to bediscarded, thus requiring the substitution of a new gear and spring,which is a unitary set-up, while under the refinement over LettersPatent above indicated the new spring can be substituted for the oldone, for use with the used gear.

A further object of the invention is the provision of a device of thischaracter, wherein it has smooth operating action, and is positive inthe working thereof for the clutching and unclutching operations, thedevice being novel in construction and is unique in the assemblythereof.

A still further object of the invention is the provision of a device ofthis character, which is simple in construction, thoroughly reliableand. efiicient in operation, strong, durable, readily and easily appliedand removed with ease and dispatch, possessed of few parts, susceptibleof quick repair, and inexpensive to manufacture and install.

With these and other objects in view the invention consists in thefeatures of construction, combination and arrangement of parts as willbe hereinafter more fully described in detail, illustrated in theaccompanying drawing, which discloses the preferred embodiment of theinvention, and pointed out in the claims hereunto appended.

In the accompanying drawing:

Figure 1 is a fragmentary side elevation of a lawn mower showing thedevice constructed in 1 Claim. (Cl. 192-46) 2 accordance with theinvention in association therewith.

Figure 2 is an end view of the gear spindle or shaft with the gear inelevation and both being broken away. l l l T Figure 3' is an elevationof the gear with the locking pin in position for locking the gear andspindle or shaft together. .2

Figure 4 is a viewsirmilar to Figure 3 showing the locking pin inreleasing position.

Figure 5 is a perspective view of the locking pin and its leaf springand removed from the gear.

-Sirnilar reference characters indicate corresponding parts throughoutthe several views in the drawing. i

,Referringto the drawing in detail, A designates generally a portion ofa lawn mower, which is-of a standard construction, having a power wheel,a portion thereof denoted at 10, while in internal toothed meshingengagement with such-wheelis the driven pinion ll, havingthe lockingdevice, indicatedgenerally. at B, as constituting the refinement overthe subject matter of Letters Patent No. 2,383,696. This device B is foroverrun clutch engagement of the pinion I l with the driving spindle orshaft 12, for operating the lawn cutter element, not shown, of the mowerA.

The device B, comprises a roller-like lockingpin l3 having a halfcircular shaped area 14 and an opposite upwardly or outwardly arched orconvexed remaining area l5, respectively. Intermediate of the length ofthis pin l3 and merging with the same at the convexed area I5 is anarrow gage ear I6, to which is fixed one end of an open loop-formationleaf spring 11, which formation is best seen in Figure 5 of the drawing.The spring I! is detachably fastened to the ear It by a fastener l8, andthis attache-d end of such spring is superimposed upon the said ear. Theinherent resiliency of the spring I! is effective for clutch seatingoperation of the pin 53, as hereinafter described.

The gear pinion ll internally thereof concentric to the center bore forthe reduced end IQ of the spindle or shaft [2 is formed with an annularchannel 20 opening into such bore and of a width for the seating of thespring I! within such channel, the latter being centered in the pinion II to intersect the bore midway of its length. The pinion II is rotatablyjournaled on the end IQ of the spindle or shaft I2 and retained thereonby a removable retaining screw 2| and companion washer 22, respectively,the screw being tapped into the end l9, as best seen in Figure 2 of thedrawing.

Built into the pinion ll crosswise of the chan- 3 nel 20 forintersecting the same and communication with the bore for the reducedend I9 is an escapement notch 23, which is of a length slightly greaterthan the length of the pin I3 for the loose seating of the lattertherein. This notch 23 is formed with a stepped double camming ceilingproviding deep and shallow communicating segmental shaped cam surfaces24 and 25,, respec tively, for over-riding'or overrunning the pin I3 toforce the latter into seating engagement, selectively, in semi-circularshaped locking grooves 25, formed spaced from each other peripheriallyin the reduced end I9 of the spindle or shaft I2. In this manner aclutching action and unclutchi-ng operation is had between the pinion Hand the.- said shaft I2, accordingly to the direction of rotation ofsuch pinion, the pin t3 being the locking" medium. 7

The device B functions as an over-run clutch between the pinion II andthe shaft I2, the action of the pin I31 with its spring- I! being bestseen in Figures 3 and 4 of the drawing, The spring: serves as a clipabout the. spindle or shaft l2, and also as an anchor for the pin 3) andthe tensioning thereof for its proper operation. In

one direction of rotation of the pinion it it is automatically locked tothe spindle or shaft t2, while in reverse rotation, the said. pinionltlf is freed from clutch engagement with the aid spindle or shaft I12.

It should be apparent that the gear forms end walls'to the notch 23 toretard end thrust of the pin I3, the latter being at all times inposition for registry with the grooves 26 and confined partially Withinthe said notch.

Thepin l3 and its spring I? is an assembly with the gear or pinion II ondetaching the latter from the spindle or shaft I2, and also'forconvenient replacement, such pinion H and the pin I? beinginterchangeable from one end to the other of the spindle or shaft I2.The assembly is practically dirt proof, as well as dust proof.

The assembly of the pin I3 and the spring I! with the pinion I I, is hadwith dispatch, the said spring expands and seats itself against theceiling of the groove or channel 20. The shallow of the notch 23 Wedgelocks the pin I3 in clutching position, while the deep surface 24permits escapement activity or unclutching operation of this pin;

The ear I6 as provided on the pin I3 enables the spring I1 to bedetached from the latter in event the said spring becomes unfit forservice, and additionally this ear reinforces the spring at the pointwhere the greatest strain occurs, and permits the assembly of theseparts with ease and dispatch The arched area of the pin assures a morepositire clutching action of the pin I3, and avoids any slippage of thepin resultant from grease formation between the gear or pinion and suchpin.

Whatis claimed is:

A device for a gear and a shaft rotatably supporting the same,comprising a roller-like locking pin. interposed between the gear andshaft, and having a half circular shaped area and an arched oppositearea, respectively, a loop-like spring about the shaft, an earprojecting from the pin between the areas, a fastener connecting thespring to the ear for the detachable carrying of the said spring by thelatter, and effecting tensioning action of the said spring on the pin,the gear being formed with a channel receiving the spring, the shaftbeing formed with pin seats concentrically thereof, and a cam surfaceonthe gear for urging the pin into locking engagement in one of theseats and also for permitting escapement of such pin from thesame ondetermined.- directions of rotation of either the gear or shaft.

ALBERT E, THOMPSON, Administrator of the Estate of Francis Edwa dThompson, Deceased.

